1. Field of the Invention
This invention relates to an agricultural rake device, specifically a Bifold or V-rake type. In one non-limiting embodiment, the Bifold rake is used for raking hay.
2. Description of the Related Art
Agricultural rakes are used to form windrows from cut crops, such as, for example, hay, straw and grasses. It is a typical agricultural process to cut these crops, rake or merge them into windrows where additional drying may occur, collect and store the crops, and subsequently feed the crops to livestock.
Modern power equipment for raking cut forage employs rotating tined wheels and particularly banks of rotating tined wheels that are moved through a field of cut forage to form windrows. These banks of wheel rakes can be quite wide to reduce both the time and number of passes required to rake a field. Because of the wide widths employed by rakes, they typically will have pivot points on each rake arm in order to fold to a narrower width for transport. Wide rakes thereby offer a potential time and cost savings to agriculture and enhance the raking process to best utilize favorable weather conditions, or to maximize the capacity utilization of the next piece of hay raking equipment.
The wide rakes require longer rake arms to support the banks of tined wheels required for efficient raking. Each rake arm includes a number of tined rake wheels which contact the ground in a working position, and serve to rake crop material into a center windrow while being pulled through a field of cut hay or alfalfa. These long rake arms can be heavy and cumbersome both in operation and in transport. While in operation, the bifold rake arms are normally spread in a “V” shape with the open end of the “V” facing forward in the direction of travel. When in transport, the machine must be configured to be much narrower. Therefore, the rake arms must pivot and/or fold.
Several different folding arm configurations are conventionally used to extend and retract the rake arms between a working position and a transport position. One common folding arm configuration can be referred to as a ‘T’ arrangement, where a fixed rear frame assembly is attached to the tongue at the rear of the v-rake opposite the hitch and positioned perpendicular to the direction of travel. This rear frame assembly sometimes telescopes to create a wider stance during operation, but is fixed at a 90-degree angle to the tongue. The rake arms are pivotally mounted on the ends of the fixed rear frame assembly, and can pivot between the working position and the transport position. A pair of transport wheels is also mounted at or near the ends of the rear frame assembly, and these wheels do not significantly change position when the rake arms are extended. The width of the rear frame assembly and thus the transport wheels is usually close to the maximum transport width, to provide stability for the equipment.
A second folding arm configuration is a “Y” arrangement and is commonly used on rakes where the rake arms are only attached to the frame in one place. This arrangement includes a pair of rear arms, which are pivotally attached to the rear end of the tongue at one end, and pivotally attached to the rake arms at the other end. The rear arms are both typically angled rearward from the tongue, forming a “Y” shape. When the rear arms are moved to a working position, the rake arm pivots, moves primarily outward, and slightly forward. Because the rake arms are only attached at this one pivot point, the angle of the rake arms must be controlled by another means, usually a hydraulic cylinder.
Certain systems with wheels at the rear of the equipment during operation such as in the “T” arrangement can render the unit long and cumbersome to steer and turn in the field in some circumstances. Some manufacturers incorporate a telescoping tongue to help bring these rear wheels slightly forward during operation, but this is a compromise of strength on the tongue member.
Certain “T” configurations have a wheel width that changes little between working and transport positions since the wheels are located very near the rear pivot point. This fixed wheel width may be a disadvantage in a working position when it is more desirable for the rear wheels to be as wide as possible while raking in the field.
The “T” configuration is also typically fairly low to the ground, limiting the distance for the crop to flow under. While the rear frame assembly can be raised, the taller configuration is usually a compromise of strength between the tongue and the supporting wheels.
In the “Y” arrangement, the transport wheels can typically be spread wider during operation. However, they usually do not move substantially forward. Therefore, the rake can be long and cumbersome to steer and turn in the field. The rake arms are usually separately controlled with hydraulic cylinders and attached to the arms at only one pivot point. Because of the stress put on this one pivot point, the overall size and weight of the frame and arm members is usually substantially bigger than in rakes that attach to the rake arms in at least two places.